Spark plug and ignition tester



Dec. 14 1926.

W. S. WITTER SPARK PLUG AND IGNITION TESTER Filed Jan.

INVENTOR. WILLIAM S. NITTER A TTORNE Y.

Patented id,

SPARK TELUG All-TD IGNITIGN TESTER.

Application filed January 2, 125.

This invention relates to spark plug. and

i gnition testers.

The general object of the invention to provide an improved mechanism for indicating the efficiency of the spark plug of agasoline engine and particularly those engines which are employed in automobiles.

One of the specific objects of the invention is to provide a tester wherein an im- 10. proved selecting mechanism for-testing the various spark plugs of an automobile engine is employed and wherein the selecting mechanism may be mounted on the cowlboard of an automobile.

A further object of the invention is to provide an improved spark plug tester wherein a. rotatable member is provided with an electrode which is arranged spirally thereon to provide-a spark gap of varying width.

A further object of the invention is to provide a spark plug tester including a condenser and a rotary electrode which are so arranged that' upon action thereof spark gaps of varying lengths may .beprovided for discharge into the condenser.

Other objects of the invention will be apparent from the following descriptiontaken in connection with the accompanying drawings wherein Fig. 1 is a central sectional view through a selector embodying the features of my invention; Fig. 2 is an end view of the selector; Fig. 3 is a central sectional 'view through the spark tester; Fig. i is an elevation of the rotor; Fig. 5 is a fragmentary section in detail; Fig. 6 is an end view showing my invention as applied to the cowlboard and Fig. 7 is a wiring diagram.

Referring to the drawing by reference characters I have shown a portion of an automobile which may be a cowlboard at 10. This .cowlboard is recessed to receive a spark tester 11. The spark tester comprises a body portion 12 which is cylindrical and which is preferably made of insulating material such as a condensation product of phenol. Upon the outerportion of the tester I arrange a brass or other metal member 14. This member may be connected through a lead 15 with a suitable ground.

' Arranged within the member 121 provide another tubular metallic member 16 which is closed as at 17 Upon the closed portion I punch out a portion 18 and in this portion 1 secure a collar 19 which as shown particularly in Figure 5 is threaded to receive a Serial No. 101.

threaded fastening member or shaft. The shaft 20 is provided with a shoulder portion 21 which engages a plug 22 to hold the plug in place. As an auxiliary means of holding the plug 22 in'place, I provide a ring 23 which may be of horn. This ring is split and due to its resiliency it expands into'a groove in the inner surface 12. I

The shaft 20 is fitted within a sleeve 25 65 which is of such metal as to form a good conductor of electricity. Mounted between the end of the sleeve 25 and the head 26 of the member 20 I show aspring 27, which normally serves to keep a rotor 30 in place. This rotor 30 is adapted to rotate about the axis of the shaft 20. A plug 31 serves to close the end of the aperture in which the shaft 20 is contained. The rotor 30 which is shown in detail in Fig. 4 is provided with a hand engaging knob 32, a flange 33, a cylindrical indexsurface 34k and a cylindrical portion 85 for fitting over the sleeve 25.

. Arranged upon the periphery of the cylindrical portion 34E 1 show an. electrode 87. This electrode is of metal which is a good conductor of electricity and the electrode is arranged spirally about the cylindrical surface 30 so that the distance from the end of thecylinderto the electrode varies about the periphery of the cylinder. The inner end of the electrode 39 extends through the cylinder 34: and engages the sleeve 25 as shown in Fig. 3. The construction is such that the spring 27 serves to hold the rotor 30 in place m as it rotates about the member 20.

(last integral with the member 12 1 provide a disc which is provided with securing apertures 51 therein to receive fastening members such as screws. Cast integral with 0 the disc is a cylindrical socket holding mem-' ber 52 which receives a socket member 53. The socket member is adapted to receive a companion member 54 secured on a lead 55 as shown. The socket memberis in communication with the lead 56, the end point 57 of which is spaced a slight distance from the end 38 of the rotor 30. .From the construction it will be apparent from Fig. 3 that when lead 55 is in circuit with a source of electricity and the rotor is turned about its axis a spark gap of-varying width will be provided between the point 57 and the electrode 37. i 1

lfnsomuch as the member 12 is. of insulating material while the members 1d and 16 are conductors of electricity the member 12 in Fig. 3 a spark plug may be connected by the lead and the lead 15 may be connected with the ground. Beginning with the rotor 30 in position so that the cl,ctrode is adjacent the point 5", the spark will jump across the gap provided. As the rotor is turned the width of the spark is increased and by turning the rotor until the spark no longer bridges the gap the condition of the spark plugs may be ascertained. In testing with my device, the rotor is turned until the sparkwill no longer bridge the gap on the tester. If no spark occurs at the first or second graduation, this indicates that the spark plug is out of commission. If, it the first or second graduation, a spark will appear, but will not appear at the third or fourth graduation, this will indicate that the spark gap on the plug is narrow or that the battery is weak. If the spark jumps at the third or fourth graduations but does not jump at a higher graduation it will indicate that the spark plug is in good working order. If the spark continues to jump until the seventh or eighth graduation is reached, this will indicate that an oversize gap is present in the spark plug. It the spark is irregular in jumping this indicates probably a terminal along the battery wires is loose. Ihe' spark appearing across the spark gap in the tester is 01 substantially the same condition as the spark which appears on the spark plug so that the condition oi the spark on the spark plug can be determined. In using my device I test the coil and the spark plugs in rotation. This will show me the general condition of the battery by the average result produced. After this preliminary test is made, I test each spark plug and compare it with the results previously obtained. The test should preterably be made when the engine is working under power as is present when the automobile is climbing a hill. In order that the spark may be readily seen I provide a lens which is held in position above the spark gap by a collar 61 and a split ring 62. A suitable arbitrary scale 63 may be market on the rotor to indicate the relative width of the spark gap.

In order that my device may be used to test the cylinders of a gasoline engine and also may be used to test the coil, I use the selector shown in Fig. 1 wherein a body portion 65 is mounted on the cowlboard. This body portion'is provided with a plurality of apertures 66 here shown as seven in number. In each of the apertures I mount a bolt 68, a nut 69 of which engages a contact 70 on a lead 71. The seven leads 71 thus provided may be arranged to take current from the distributor or they may go to each spark plug independently with one of the leads arranged in circuit with the coil 71 as shown in Fig. 7

Mounted within a recess 72 I show a cylin drical rotor 73. This rotor is mounted on a shaft 74. by means of a plug 75 which is engaged by a spring 7 6. The construction is such that the rotor 73 may be pulled outwardly to the dotted line position shown in Fig. 1 thus allowing it to be turned and upon release it may assume the position shown. The shaft 7 is electrically connected with a lead 86 and also connected with a circuit closure 81 which is adapted to en gage the heads of the members 68 as shown in F 1. The lead may be connected with the condenser as shown in the wiring diagram in Fig. 7.

Arranged about the periphery of the rotor 7 3 I show a groove 83 and in this groove I arrange numerals 84:. These numerals are so arranged that when each is brought into registry with the arrow 85 (see Fig. 6) the cylinder corresponding with the number on the index will he in circuit with the tester. The selector enables any one of the spark plugs or the coil to be placed in circuit with thetester so that the condition of the spark plug or the coil may be determined.

Having thus described my invention, I claim:

1. A spark tester comprising a body portion of insulating material, said body portion having an interior lining and having an exterior cover, said lining and said cover being made of metal, a closure for said body, said closure having a rotor secured thereto, a shaft on which said rotor is mounted, an electrode mounted upon said rotor, a stationary electrode, the relation of said stationarv electrode and the electrode on said rotor being suchthat as the rotor is turned a spark gap of varying width is provided, and means to connect the exterior cover with a ground.

2. A spark tester comprising a body portion of insulating material, said body portion having an interior lining and having an exterior cover, saidcover being grounded. said lining and said cover being made of metal, a rotor secured to said body, an electrode mounted upon said rotor. a stationary electrode, the relation of said stationary electrode and the electrode on said rotor bein such that as the rotor is turned a spark gap of varying width is provided, means to connect said stationary elect-rode with a source of electricity and means to place said movable electrode in circuit with the interior lining of the body.

3. A testing device, said device including a fixed electrode, a body of insulating material having inner and outer metallic coverings to provide a condenser, a rotor mounted on said body, said rotor including a ho]- low cylindrical portion having an electrode thereon arranged upon the periphery thereof and ad acent said fixed electrode, means to vary the distance from said fixed electrode to said other electrode and means to place said movable electrode in circuit with one of the elements of the condenser.

4;. A spark tester having a body of insulating material, said body being of cylindrical form, an outer cover of metal on said body, a lining of metal within said body, a closure for said body, 'a shaft secured to said closure, a bushing on said shaft, a rotor mounted to rotate with said bushing, a head on said shaft, a spring between said head and the end of said bushing, said rotor having a cylindrical outer surface, an exposed electrode on the outer surface of said rotor, a fixed electrode in said body, the end of said fixed electrode being spaced from the end of said rotor whereby the distance between the end of said fixed electrode and the adjacent part of the electrode on the rotor will vary as the rotor is turned, a lensarranged over said fixed electrode and a socket associated with said fixed electrode.

In testimony whereof, I hereunto alfix my signature.

WILLIAM S. WVITTER. 

